Project Meeting 2016.09.09 - ActivitySim/activitysim GitHub Wiki

#Task 1 Project Management

• Elizabeth (@e-lo) is available to review in November. This should correspond well with our progress on task 10

#Task 7 Nested Logit

• Completed addition of LOGIT_TYPE setting for simple simulate models so the user can easily switch between MNL and NL
• Documentation updated as well
• Task complete

#Task 10 Full Model Run

• Bill planning to send contract amendment to RSG next week
• Improved error handling and reporting when logit utilities are inf or probabilities don't sum to 1. We now print out the ids the (first 50) offending rows to enable tracing/debugging.
• Ran for full model run with this additional feature and CDAP is failing for HHs with 17+ members since it is trying to build pandas data frames with 3^17 column (~129m)
• CDAP is implemented incorrectly - it is supposed to only consider the interactions between up to 5 HH members and then apply some additional utility terms after that
• We will review the MTC TM1 code and UECs and correct this
• CDAP currently loops by HHs but this is inefficient
• We will likely re-implement it as a series of batch vectorized calculations:
  • Select the 5 persons for consideration in HHs with 6+ people; select workers and youngest kids
  • Calculate person level utilities
  • Calculate HH level utilities
  • Calculate Person pairwise utilities for HH size 1
  • Calculate Person pairwise utilities for HH size 2
  • Calculate Person pairwise utilities for HH size 3
  • Calculate Person pairwise utilities for HH size 4
  • Calculate Person pairwise utilities for HH size 5
  • Sum up utilities at the HH level
• The key is to organize the problem into a series of batch table operations
• SANDAG's CDAP model UEC includes a joint tour model page but this is just for convenience in order to reuse the Java DMU attributes. The SANDAG CDAP model does not include anything related to joint tours.